LCP: timeout sending Config-Requests

This is a general error condition that is common to a number of causes. It means that pppd did not receive any LCP configuration requests from the peer, or was unable to agree on LCP parameters. Enable debug logging, try the connection again, and look at messages just prior to this message.

There are many causes for the timeout error:

MSCHAP negotiation failed,

no GRE packets were received by the client,

no GRE packets were transmitted by the server,

invalid GRE packets were transmitted by the server,

no GRE packets were transmitted by the client.

invalid GRE packets were transmitted by the client,

Use tcpdump to check the flow of GRE packets.

Reference

http://pptpclient.sourceforge.net/howto-diagnosis.phtml#lcp_timeout